The magnificent obsession: man takes over a decade to design and build a Boeing 777 model out of paper

Yes, it’s made entirely out of paper: manila folders.

The YouTube notes:

Over the last decade, designer Luca Iaconi-Stewart has been building an incredibly detailed model of a Boeing 777, right down to the tiny seats and moving landing gear, using only paper folders and glue.

40 Comments

But (I can’t help it!): Did he put in the steering mechanism on the main landing gear?

Just kidding! 🙂 (Not about the MLG steering mechanism though, they have those on the 777: The scrubbing torsion is just too high otherwise with three axles — as the A-380 designers found out the hard way.)

That’s what occurs when the plane is not oriented precisely with it’s direction of travel as it touches down, which is very often the case. This occurs when winds are not aligned with the runway. When this happens the tires are subjected to lateral forces because they are not pointing in the same directon the plane is actually moving, which results in twisting, or torsion, in the landing gear struts. The plane quickly becomes oriented with its direction of travel when it touches down, with much screeching tires and smoke, unless the landing gear break.

The problem can be serious enough for heavy planes that they make the rear landing gear steerable so that they can be oriented off the center-line of the airplane and point in the direction of travel in order to reduce torsion in the landing gear struts.

I may not be exactly correct on this but the steering is with the noise wheel. The main gear which are three axles in tandem need to allow for a small movement left and right as the airplane turns on the ground to avoid scrubbing rubber, which would happen if they were ridged. However it would also be useful/required as you point out in a cross wind landing. The movement left or right would be controlled by the rudder pedals.

For three axles in a row – in a crosswind landing all three axles would want to rotate by the same amount in the same direction to avoid yanking the plane ‘sideways’ against the wind.

When turning tightly (with the nosewheel steering) the front and rear axles would want to rotate in opposite directions so that the three wheels in a row would follow the curve. Multi-axle trucks or trailers often incorporate this sort of mechanism.

I do not know either but I would guess the second option, steering on the ground because they must do this all the time. A strong crosswind that would require the other type steering would not happen frequently. Next time I run into an aircraft engineer I will ask about this. Here in Wichita we do have a few.

I was also going to say but forgot – landing in a strong crosswind does require crabbing into the wind but in a small plane, you quickly straighten just as the wheels are about to tough the runway. Again, I will ask around.

“A strong crosswind that would require the other type steering would not happen frequently.”

It happens frequently enough for Youtube to be full of it, as Rickflick noted below.

I think pilots of large planes do try to straighten out just before they hit… err, sorry, touch down, but the timing must be quite critical. Ideally, so that they’re straight on impact but before there’s been time for the wind to give them an appreciable sideways (downwind) velocity.

There are lots of YouTube videos of these large passenger jets in cross wing landings. They are hard to watch for me as a pilot of a single engine recreational plane. We want to dip the upwind wing and proved opposite rudder to prevent the cross wind from tipping the plane over and keeping it relatively aligned with the center line. It’s tricky though since you don’t usually have a strong sense of alignment while looking over the nose. One can only keep trying to get it right and hopefully improve.

[The B52 “Buff”] has steerable dual-bicycle gear which allows the crew to point the gear along the runway while the fuselage is “crabbed” up to 20 degrees off the runway centerline. AFAIK the gear are slaved to the ILS; you dial in the OBI to a course and the gear will point that way even if the aircraft points differently.

The reason this was done is primarily due to the design of the rest of the aircraft. It’s a very “dense” design, cramming a lot of weight into a very small package, requiring massive wings and tail just to keep the thing under control at altitude. These surfaces then become huge sails at lower altitudes, and with the high, anhedraled wing arrangement on a relatively low fuselage, there’s not much room for error. B-52 pilots often say you have to fly 2 seconds ahead of the plane, it’s that slow to react to pilot input. So, classic “de-crabbing” techniques involving a hard rudder with counter-aileron just aren’t going to work with a BUFF. You have to land crabbed and correct after touchdown, and on a dry runway that isn’t a good idea either with an aircraft of this size.

Modern airliners, for their size, are much easier to manoeuvrer on the whole than the BUFF. Really big ones, like the 747, actually have steerable main gear as well, but AFAIK the 747’s mains can only be actively steered on the ground, and because they counter-steer to the nose gear (helps bring the tail around corners; imagine driving something about 4 times longer than an 18-wheeler) they would actually be pointed further off the runway line when de-crabbing.

Four- and six-wheel main gear systems used on larger airliners (777, 787, A380) actually have a small amount of castoring built in; if you watch YouTubes of crosswind landings (there are several) you’ll see that the rear two wheels of each gear touch first and actually twist the entire “truck” into line with the aircraft’s actual direction of travel. Then as the plane settles on the gear and the fuselage lines back up with the runway, they’ll straighten. Planes with one- and two-wheel main gear don’t need this as much (and such a system isn’t as effective as the first point of contact of a tire is directly level with the gear strut instead of behind it)

Here is a short, fun video of a B52 performing a crab landing with landing gear orientated to the runway centreline:

Apparent source, but it’s a quote of a quote of a quote so I’m not providing a link: Air Transport Intelligence news “A380 tyres withstand extreme handling tests: Airbus London, 15th July 2005”

Airbus is claiming that the undercarriage and tyres on its A380 aircraft have performed as expected after being subjected to extreme ground-handling tests last month.

Images show that the tests resulted in deformation and damage to the aircraft’s Michelin tyres but that they performed “at and above” expected levels during the abusive ground-handling tests on 25 June.

The A380 main undercarriage comprises two four-wheel under-wing bogies and, behind them, two six-wheel fuselage-mounted bogies. The rear axle of the six-wheel bogie is normally steerable during push-back and taxiing.

But unless electrical power is supplied to the aircraft during towing – by the aircraft or from generators on the tow-tractor – the axle remains locked.

Airbus states that the undercarriage tests were designed to take the undercarriage and tyres “way beyond the limit of normal operations” and adds: “[The tests] were the equivalent of the structural static airframe tests to destruction.

“Although these tests were designed to test up to maximum deformation and beyond, the gear did exactly what it is supposed to do”

Also, please CLICK ON THIS LINK to view a picture from the test of the effect on the runway tarmac of towing an A380 [I assume in a turn] with the steerable axles locked to maximise the strain on the system.

Very cool. My kids would take less than 10 minutes to completely destroy it.

It reminds me of what captured British sailors did in French prisons during the Napoleonic Wars: They built large exact replicas of their ships from memory using only discarded chicken bones. Recently they inserted laproscopes into the interior of one of the ships and found that the interiors were exact even though the sailors must have believed no one would ever see the interiors.

Remember that, stunning work, and the little anachronism of WEIT.
How long do you take to make such a diorama? Do you work at it full time, or just, say, a day a week?
Please give us a link to the photos of your Samurais?

Amazing project and patience. Hard to see how he used this paper to make some of the parts, such as the cylinders on the landing gear and the steering. Making all of the ribs in the fuselage and wings from scratch! They design all of this on computers now and he does it all by hand. A good friend of mine was a pilot on this model, the 777. He died of cancer in 2005.